21322871 has 2 divisors, whose sum is σ = 21322872. Its totient is φ = 21322870.

The previous prime is 21322849. The next prime is 21322891. The reversal of 21322871 is 17822312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21322871 - 2²² = 17128567 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21322871.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21322891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661435 + 10661436.

It is an arithmetic number, because the mean of its divisors is an integer number (10661436).

Almost surely, 2^21322871 is an apocalyptic number.

21322871 is a deficient number, since it is larger than the sum of its proper divisors (1).

21322871 is an equidigital number, since it uses as much as digits as its factorization.

21322871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 26.

The square root of 21322871 is about 4617.6694338162. The cubic root of 21322871 is about 277.2991637217.

The spelling of 21322871 in words is "twenty-one million, three hundred twenty-two thousand, eight hundred seventy-one".